if may give you an advice, start painting on a non-white background.
i always start on a gray one
doing so you can better work with white highlights and black shading
the white background makes the image extremely light
i see in your image you dont hesitate to highlight with very light colors (eg. the golden sword)
but applying such highlights to the sword, it tends to blur with the white background
i quick placed your warrior dude on a brownish background
maybe you see what i mean
Greetz
D0R